According to Bibb Latané and John Darley (1970),a Number of Things

According to Bibb Latané and John Darley (1970) ,a number of things must occur before witnesses decide to intervene in an emergency situation.According to this stage model,when witnesses ____, costs of helping will be most relevant to their behavior.

A) decide whether to implement their decision to help
B) attempt to determine whether the event is actually an emergency
C) decide whether they are personally responsible to intervene
D) decide whether they have the necessary skills to intervene